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#include#include // 定义module_param module_param_arrary 函数的头文件#include // 定义参数函数中perm 参数的枚举量头文件#include // MKDEV 转换设备号数据类型的宏定义#include // 三个字符设备号函数#include // 定义字符设备的结构体#include #defind DEVICE_NAME "scdev";#defind DEVICE_MINOR_NUM 2;#defind DEVICE_MAJOR 0;// 主设备号#defind DEVICE_MINOR 0;module_init(sdev_init);module_exit(sdev_exit);static int module_arg1,module_arg2;static int int_array[50];static int int_num;int numdev_major = DEVICE_MAJOR;int numdev_minor = DEVICE_MINOR;/**/// 输入主设备号module_param(numdev_major,int,S_IRUSR);// 输入次设备号module_param(numdev_minor,int,S_IRUSR);static int sdev_init(void){ int ret = -1; dev_t num_dev; if(numdev_major){ num_dev = MKDEV(numdev_major,numdev_minor); ret = register_chrdev_region(num_dev,DEVICE_MINOR_NUM,DEVICE_NAME); }else{ printk(KERN_EMERG,"\t numdev_major %d is failed\n ",numdev_major); } if(!ret){ printk(KERN_EMERG,"\t register_chrdev_region req %d is failed\n ",numdev_major); } printk(KERN_EMERG,"\ cdev enter!\n "); return 0;}static int sdev_exit(void){ printk(KERN_EMERG,"\t cdev is:%d\n ",module_arg2); unregister_chrdev_region(MKDEV(numdev_major,numdev_minor),DEVICE_MINOR_NUM); return 0;}
# 使用命令 cat/proc/devices 查看已经被注册的设备号,设备号9 没有被注册cat /proc/devcies # 带参数加载模块insmod /mnt/udisk/request_dev_num.ko numdev_major=9 numdev_minor=0# 查看设备号9cat /proc/devcies 写在模块
#include#include // 定义module_param module_param_arrary 函数的头文件#include // 定义参数函数中perm 参数的枚举量头文件#include // MKDEV 转换设备号数据类型的宏定义#include // 三个字符设备号函数#include // 定义字符设备的结构体#include #defind DEVICE_NAME "dcdev";#defind DEVICE_MINOR_NUM 2;#defind DEVICE_MAJOR 0;// 主设备号#defind DEVICE_MINOR 0;module_init(sdev_init);module_exit(sdev_exit);static int module_arg1,module_arg2;static int int_array[50];static int int_num;int numdev_major = DEVICE_MAJOR;int numdev_minor = DEVICE_MINOR;/**/// 输入主设备号module_param(numdev_major,int,S_IRUSR);// 输入次设备号module_param(numdev_minor,int,S_IRUSR);static int sdev_init(void){ int ret = -1; dev_t num_dev; if(numdev_major){ // 如果0 则动态申请 num_dev = MKDEV(numdev_major,numdev_minor); ret = register_chrdev_region(num_dev,DEVICE_MINOR_NUM,DEVICE_NAME); }else{ ret = allo_chrdev_region(&num_dev,numdev_minor,DEVICE_MINOR_NUM,DEVICE_NAME); numdev_major = MAJOR(num_dev); printk(KERN_EMERG,"\t numdev_major %d is failed\n ",numdev_major); } if(!ret){ printk(KERN_EMERG,"\t register_chrdev_region req %d is failed\n ",numdev_major); } printk(KERN_EMERG,"\ dcdev enter!\n "); return 0;}static int sdev_exit(void){ printk(KERN_EMERG,"\t cdev is:%d\n ",module_arg2); unregister_chrdev_region(MKDEV(numdev_major,numdev_minor),DEVICE_MINOR_NUM); return 0;}
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